High-precision laser cutting machine and control system thereof

Abstract

The invention relates to the field of laser cutting machines, in particular to a high-precision laser cutting machine and a control system thereof, and aims to solve the problems that deviation exists between an actual laser moving path and a preset path and is not easy to find due to aging and abrasion of a control assembly during use of the laser cutting machine. According to the laser cutting device, cutting is conducted by fixing the laser emitting assembly and moving the workpiece clamping assembly, so that the moving path of the workpiece clamping assembly is convenient to collect, control points are selected from the image of the workpiece clamping assembly according to the collected image, the control points are analyzed frame by frame, and control point moving vectors between different frames are obtained; according to the method, the moving path of the control point is tracked according to vector superposition, combination and vector difference calculation, and the moving path is compared with the preset output path, so that the deviation condition of path control in the cutting process is found in time, and the cutting path precision of the laser cutting machine is improved conveniently.

Description

Technical Field

[0001] The present invention relates to the field of laser cutting machines, in particular to a high-precision laser cutting machine and a control system thereof. Background Art

[0002] The laser cutting machine is a machine that focuses the laser emitted from the laser into a high-power density laser beam through the optical path system. The laser beam irradiates the surface of the workpiece, causing the workpiece to reach the melting point or boiling point, and at the same time, the high-pressure gas coaxial with the beam blows away the molten or vaporized metal. As the relative position of the beam and the workpiece moves, a slit is eventually formed in the material, thereby achieving the purpose of cutting. Laser cutting replaces the traditional mechanical knife with an invisible beam, and has the characteristics of high precision, fast cutting, no restrictions on cutting patterns, smooth incisions, and low processing costs. It will gradually improve or replace traditional metal cutting process equipment;

[0003] At present, the laser cutting machines in the prior art still have some shortcomings. A five-axis high-precision laser cutting machine is disclosed in the patent document with the publication number CN113953677B. In this solution, the workpiece to be cut is automatically fixed by components such as a slot and a cylinder, which ensures that the workpiece will not be offset during cutting and improves the cutting accuracy. However, in actual use, the control components of the laser cutting machine will age with the increase of use time, so that during the laser cutting process, although the workpiece does not deviate, the moving path of the laser deviates from the moving path set in the numerical control system. Such deviations are not easy to be discovered because the deviation value is small and there is no effective monitoring means, which further affects the cutting accuracy of the laser cutting machine in high-precision cutting tasks.

[0004] In view of the above technical problems, this application proposes a solution. Summary of the invention

[0005] In the present invention, cutting is performed by adopting a fixed laser emitting component and a mobile workpiece clamping component, so that the moving path of the workpiece clamping component is easy to collect, and control points are selected in the image of the workpiece clamping component according to the collected image, and the control points are analyzed frame by frame to obtain the control point movement vector between different frames, and the control point movement path is tracked according to the vector superposition, combination and vector difference calculation methods, and the actual movement path is generated according to the tracking of the control point movement path, and the movement path is compared with the preset output path, so as to timely discover the deviation of the path control during the cutting process, which is convenient for improving the cutting route accuracy of the laser cutting machine, and solves the problem that the actual movement path of the laser deviates from the preset path due to aging and wear of the control component during use of the laser cutting machine and is not easy to be discovered, and a high-precision laser cutting machine and its control system are proposed.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A high-precision laser cutting machine comprises an equipment body, a laser transmission cavity is installed on the upper part of the equipment body through a cross bar, a laser seat is connected to the bottom end of the laser transmission cavity, a bottom plate is fixedly installed on one side of the bottom of the equipment body, a translation frame is installed above the bottom plate, a cutting base is installed on the top of the translation frame, and the translation frame enables the cutting base to move in any direction in a plane through the coordinated movement of the horizontal and vertical axes;

[0008] The top of the laser seat is fixedly connected with an air inlet chamber, which surrounds the bottom of the laser transmission chamber. The bottom of the air inlet chamber is connected with multiple groups of blowing holes, and the directions of the blowing holes can be adjusted.

[0009] A high-precision laser cutting machine control system, comprising a trajectory acquisition unit, a trajectory verification unit, an image acquisition unit, a blowing control unit and a laser correction unit;

[0010] The trajectory acquisition unit acquires the running trajectory of the translation frame, records it as an output trajectory, and sends the output trajectory to the trajectory verification unit;

[0011] The image acquisition unit acquires the motion image and the cutting image of the cutting base, and obtains the control points and the coordinates of the control points of the cutting base through the motion image. The image acquisition unit analyzes the control points in the motion image frame by frame to obtain the control point coordinate set. The image acquisition unit analyzes the cutting image to extract the cutting seam width and the protruding impurities in the cutting image.

[0012] The trajectory verification unit obtains a control point coordinate set through the image acquisition unit, and obtains an actual moving path through the control point coordinate set, compares the actual moving path with the output trajectory, and generates a path verification signal;

[0013] The blowing control unit obtains the protruding impurities through the image acquisition unit and controls the blowing according to the number of the protruding impurities;

[0014] The laser correction unit obtains the cutting seam width through the image acquisition unit, and generates a cutting abnormality signal or a cutting normal signal according to the cutting seam width, and simultaneously generates a laser contraction signal or a laser amplification signal.

[0015] As a preferred embodiment of the present invention, the control points acquired by the image acquisition unit are respectively a first control point, a second control point, a third control point and a fourth control point, and the four groups of control points are respectively four corner points of the cutting base in the starting frame of the motion image;

[0016] The method for the image acquisition unit to obtain the control point coordinate set is:

[0017] The image acquisition unit creates a plane coordinate system with the center of the picture as the origin, and expresses the position of each acquired control point in the form of coordinates to obtain a first control point coordinate set, a second control point coordinate set, a third control point coordinate set and a fourth control point coordinate set.

[0018] As a preferred embodiment of the present invention, the method for the trajectory checking unit to generate the actual moving path is:

[0019] The trajectory checking unit performs difference calculation on two adjacent sets of coordinates in a set of control points to obtain a horizontal axis difference and a vertical axis difference between the two adjacent sets of coordinates, and performs vector superposition according to the horizontal axis difference and the vertical axis difference to obtain a control point change vector. The trajectory checking unit performs difference calculation and vector superposition on the two adjacent sets of coordinates in the control point set in turn to obtain multiple sets of control point change vectors, and records them as a first control point change vector STn, a second control point change vector NDn, a third control point change vector RDn, and a fourth control point change vector THn, respectively.

[0020] The trajectory checking unit selects any two groups of control point change vectors with the same number n from the multiple groups of control point change vectors to perform difference calculation. If the vector difference of the change vectors is less than a preset threshold, the directions and angles of the four groups of control point change vectors are averaged to obtain a total control point change vector OVn.

[0021] The trajectory checking unit obtains all total control point change vectors and connects the starting end of OVn+1 with the end of OVn to form a complete actual moving path.

[0022] As a preferred embodiment of the present invention, the method for the trajectory checking unit to calculate the vector difference of the change vector is:

[0023] The trajectory checking unit calculates the direction deviation angle D and length difference L of the change vectors of the two groups of control points, and generates a vector difference C through formula analysis, C=(D+q)(L+j), where q and j are preset constant terms, and the value range of q and j is 3-7.

[0024] As a preferred embodiment of the present invention, the method for the trajectory checking unit to obtain vector superposition is:

[0025] The trajectory verification unit draws a line segment with a length equal to the longitudinal axis difference in the longitudinal direction, draws a line segment with a length equal to the transverse axis difference in the transverse direction, and translates the line segment in the longitudinal direction, translates the starting point of the line segment in the longitudinal direction to the end point of the line segment in the transverse direction, and then connects the starting point of the line segment in the transverse direction with the end point of the line segment in the longitudinal direction to obtain a new line segment with a direction and length, which is recorded as a control point change vector.

[0026] As a preferred embodiment of the present invention, the path verification signal generated by the trajectory verification unit includes a path verification pass signal and a path verification fail signal. The trajectory verification unit assigns a preset path width to the actual moving path and the output trajectory, and overlaps the actual moving path with the starting point of the output trajectory, and divides the output trajectory and the actual moving path into i sections. If the actual moving path and the output trajectory in the i-th section always overlap, it is recorded as a normal section, otherwise, it is recorded as an abnormal section. The trajectory verification unit counts the number of occurrences of the abnormal section in the i sections and records it as a normal ratio;

[0027] If the normal ratio is greater than or equal to the preset ratio threshold, a path check pass signal is generated; if the normal ratio is less than the preset ratio threshold, a path check fail signal is generated.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. In the present invention, during the laser cutting process, cutting is performed by fixing the laser emitting component and moving the workpiece clamping component, so that during the cutting process, the moving path of the workpiece clamping component can be detected by the image acquisition device attached to the upper laser emitting component, and the accuracy of the output path can be detected according to the moving path of the workpiece, so as to timely discover the deviation of the path control during the cutting process, which is convenient for improving the cutting path accuracy of the laser cutting machine.

[0030] 2. In the present invention, when the accuracy of the moving path of the workpiece clamping assembly is detected, control points are selected in the image of the workpiece clamping assembly, and the control points are analyzed frame by frame to obtain the control point movement vectors between different frames. The control point movement path is tracked by vector superposition, combination and vector difference calculation, and the actual movement path is generated based on the tracking of the control point movement path, so as to compare the movement path with the preset output path.

[0031] 3. In the present invention, during the cutting process, the cutting seam width and the cutting floating impurities are monitored by the images collected by the image acquisition device, so as to adjust the laser output and air volume output during the cutting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0033] Figure 1 It is a schematic diagram of the main structure of the present invention;

[0034] Figure 2 It is a schematic diagram of the structure of the air inlet chamber of the present invention;

[0035] Figure 3 is a system block diagram of the present invention;

[0036] Figure 4 It is a system flow chart of the present invention.

[0037] In the figure: 1. Equipment body; 2. Laser base; 3. Laser transmission cavity; 4. Cutting base; 5. Translation frame; 6. Bottom plate; 7. Air blowing hole; 8. Air inlet chamber. DETAILED DESCRIPTION

[0038] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Embodiment 1:

[0040] See also Figure 1 - Figure 4 As shown, a high-precision laser cutting machine includes an equipment body 1, a laser transmission cavity 3 is installed above the equipment body 1 through a cross bar, a laser seat 2 is connected to the bottom end of the laser transmission cavity 3, the laser seat 2 emits a laser beam downward from the bottom, and cuts the material through the laser, a bottom plate 6 is fixedly installed on one side of the bottom of the equipment body 1, a translation frame 5 is installed above the bottom plate 6, a cutting base 4 is installed on the top of the translation frame 5, and the translation frame 5 enables the cutting base 4 to move in any direction in the plane through the coordinated movement of the horizontal and vertical axes;

[0041] An air inlet chamber 8 is fixedly connected to the top of the laser seat 2, and the air inlet chamber 8 surrounds the bottom of the laser transmission chamber 3. A plurality of blowing holes 7 are connected to the bottom of the air inlet chamber 8, and the direction of the blowing holes 7 can be adjusted;

[0042] A control terminal is installed inside the device body 1. The control terminal includes at least a processor and a memory. The processor is used to run a high-precision cutting machine control system stored in the memory.

[0043] Embodiment 2:

[0044] See also Figure 1 - Figure 4 As shown, a high-precision cutting machine control system includes a trajectory acquisition unit, a trajectory verification unit, an image acquisition unit, a blowing control unit and a laser correction unit, wherein the trajectory acquisition unit acquires the running trajectory of the translation frame 5, records it as an output trajectory, and sends the output trajectory to the trajectory verification unit;

[0045] The image acquisition unit acquires a motion image of the cutting base 4 through a camera, and selects four corner points of the cutting base 4 in a starting frame of the motion image, marking them as a first control point, a second control point, a third control point, and a fourth control point;

[0046] The image acquisition unit analyzes the motion image of the cutting base 4 frame by frame, marks all the control points in each frame, creates a plane coordinate system with the center of the picture as the origin, and represents the position of each control point acquired in the form of coordinates, thereby obtaining a first control point coordinate set, a second control point coordinate set, a third control point coordinate set and a fourth control point coordinate set. The image acquisition unit sends the first control point coordinate set, the second control point coordinate set, the third control point coordinate set and the fourth control point coordinate set to the trajectory verification unit.

[0047] The trajectory checking unit performs difference calculation on two adjacent groups of coordinates in the first control point set to obtain a horizontal axis difference and a vertical axis difference between the two adjacent groups of coordinates, and performs vector superposition according to the horizontal axis difference and the vertical axis difference to obtain a first control point change vector. The trajectory checking unit sequentially performs difference calculation and vector superposition on two adjacent groups of coordinates in the first control point set to obtain multiple groups of first control point change vectors, wherein the first control point change vector obtained by calculating the first group and the second group of coordinates is recorded as ST1, the first control point change vector obtained by calculating the second group and the third group of coordinates is recorded as ST2, and the first control point change vector obtained by calculating the nth group and the n+1th group of coordinates is recorded as STn;

[0048] The method for vector superposition by the trajectory verification unit is as follows: the trajectory verification unit draws a line segment with a length equal to the longitudinal axis difference in the longitudinal direction, draws a line segment with a length equal to the transverse axis difference in the transverse direction, and translates the line segment in the longitudinal direction, translates the starting point of the line segment in the longitudinal direction to the end point of the line segment in the transverse direction, and then connects the starting point of the line segment in the transverse direction with the end point of the line segment in the longitudinal direction to obtain a new line segment with a direction and length, which is recorded as the first control point change vector ST.

[0049] Similarly, the trajectory verification unit performs the same steps of coordinate difference calculation and vector superposition on the second control point coordinate set, the third control point coordinate set and the fourth control point coordinate set in the same way to obtain the second control point change vector ND, the third control point change vector RD and the fourth control point change vector TH respectively.

[0050] The trajectory checking unit compares the first control point change vector STn, the second control point change vector NDn, the third control point change vector RDn and the fourth control point change vector THn in parallel. The trajectory checking unit selects any two groups of control point change vectors numbered n, calculates the direction deviation angle D and the length difference L of the two groups of control point change vectors, and generates a vector difference C through formula analysis, C = (D + q) (L + j), where q and j are preset constant terms, and the value range of q and j is 3 to 7:

[0051] If the vector difference between any two groups of change vectors in the four groups of control point change vectors is less than a preset threshold, the directions and angles of the four groups of control point change vectors are averaged to obtain a total control point change vector OVn;

[0052] If the difference between two groups of change vectors among the four groups of control point change vectors is greater than a preset threshold, an acquisition abnormality alarm is generated and sent to a display device, and a text alarm is issued through the display device.

[0053] The trajectory checking unit obtains all the total control point change vectors, connects the total control point change vectors by paths, and generates an actual moving path. The method for connecting the total control point change vectors by paths is as follows: the trajectory checking unit selects OV1, and connects the starting end of OV2 with the end of OV1, and connects the starting end of OVn+1 with the end of OVn, to form a complete actual moving path;

[0054] The trajectory checking unit assigns a preset path width to the actual moving path and the output trajectory, and overlaps the actual moving path with the starting point of the output trajectory, and divides the output trajectory and the actual moving path into i sections, where i is a natural number not equal to 0. If the actual moving path and the output trajectory always overlap in the i-th section, it is recorded as a normal section, otherwise, it is recorded as an abnormal section. The trajectory checking unit counts the number of occurrences of the abnormal section in the i sections and records it as a normal ratio;

[0055] If the normal ratio is greater than or equal to the preset ratio threshold, a path verification pass signal is generated. If the normal ratio is less than the preset ratio threshold, a path verification fail signal is generated and sent to the display device. A text alarm is issued through the display device and the laser cutting operation is stopped.

[0056] Embodiment three:

[0057] See also Figure 1 - Figure 4As shown, the image acquisition unit acquires the cutting image during the laser cutting process, and performs Hough transform algorithm recognition on the acquired cutting image, extracts the cutting gap in the cutting image, quantifies the width of the cutting gap, obtains the cutting gap width, and sends the cutting gap width to the laser correction unit;

[0058] The laser correction unit calculates the difference between the cutting seam width and the preset width threshold. If the difference between the cutting seam width and the preset width threshold is within the allowable range, a normal cutting signal is generated. If the difference between the cutting seam width and the preset width threshold exceeds the allowable range, a cutting abnormality signal is generated.

[0059] After generating a cutting abnormality signal, the laser correction unit compares the cutting seam width with the preset width threshold. If the cutting seam width is smaller than the preset width threshold, a laser amplification signal is generated; if the cutting seam width is larger than the preset width threshold, a laser contraction signal is generated.

[0060] Embodiment 4:

[0061] See also Figure 1 - Figure 4 As shown, the image acquisition unit performs defect algorithm recognition on the acquired cutting image, extracts the protruding impurities located in the cutting seam area in the image, and sends the protruding impurities to the blowing control unit;

[0062] The blowing control unit identifies the number of protruding impurities, and generates a wind force increase signal if the number of protruding impurities exceeds a preset value, and does not respond if the number of protruding impurities is less than the preset value.

[0063] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-precision laser cutting machine, characterized in that: The device comprises a device body (1), a laser transmission cavity (3) is installed on the top of the device body (1) via a cross bar, a laser seat (2) is connected to the bottom end of the laser transmission cavity (3), a bottom plate (6) is fixedly installed on one side of the bottom of the device body (1), a translation frame (5) is installed above the bottom plate (6), a cutting base (4) is installed on the top of the translation frame (5), and the translation frame (5) enables the cutting base (4) to move in any direction in a plane through the coordinated movement of the horizontal and vertical axes; The top of the laser seat (2) is fixedly connected to an air inlet chamber (8), the air inlet chamber (8) surrounds the bottom of the laser transmission chamber (3), and the bottom of the air inlet chamber (8) is connected to multiple groups of blowing holes (7), and the directions of the blowing holes (7) can be adjusted.

2. A high-precision laser cutting machine control system, applicable to a high-precision laser cutting machine according to claim 1, characterized in that: It includes a trajectory acquisition unit, a trajectory checking unit, an image acquisition unit, an air blowing control unit and a laser correction unit; The trajectory acquisition unit acquires the running trajectory of the translation frame (5), records it as an output trajectory, and sends the output trajectory to the trajectory verification unit; The image acquisition unit acquires a motion image and a cutting image of the cutting base (4), and obtains control points and control point coordinates of the cutting base (4) through the motion image. The image acquisition unit analyzes the control points in the motion image frame by frame to obtain a control point coordinate set. The image acquisition unit analyzes the cutting image to extract the cutting seam width and protruding impurities in the cutting image. The trajectory verification unit obtains a control point coordinate set through the image acquisition unit, and obtains an actual moving path through the control point coordinate set, compares the actual moving path with the output trajectory, and generates a path verification signal; The blowing control unit obtains the protruding impurities through the image acquisition unit and controls the blowing according to the number of the protruding impurities; The laser correction unit obtains the cutting seam width through the image acquisition unit, and generates a cutting abnormality signal or a cutting normal signal according to the cutting seam width, and simultaneously generates a laser contraction signal or a laser amplification signal.

3. A high-precision laser cutting machine control system according to claim 2, characterized in that: The control points acquired by the image acquisition unit are respectively a first control point, a second control point, a third control point and a fourth control point, and the four groups of control points are respectively four corner points of the cutting base (4) in the starting frame of the motion image; The method for the image acquisition unit to obtain the control point coordinate set is: The image acquisition unit creates a plane coordinate system with the center of the picture as the origin, and expresses the position of each acquired control point in the form of coordinates to obtain a first control point coordinate set, a second control point coordinate set, a third control point coordinate set and a fourth control point coordinate set.

4. A high-precision laser cutting machine control system according to claim 2, characterized in that: The method for the trajectory checking unit to generate the actual moving path is: The trajectory checking unit performs difference calculation on two adjacent sets of coordinates in a set of control points to obtain a horizontal axis difference and a vertical axis difference between the two adjacent sets of coordinates, and performs vector superposition according to the horizontal axis difference and the vertical axis difference to obtain a control point change vector. The trajectory checking unit performs difference calculation and vector superposition on the two adjacent sets of coordinates in the control point set in turn to obtain multiple sets of control point change vectors, and records them as a first control point change vector STn, a second control point change vector NDn, a third control point change vector RDn, and a fourth control point change vector THn, respectively. The trajectory checking unit selects any two groups of control point change vectors with the same number n from the multiple groups of control point change vectors to perform difference calculation. If the vector difference of the change vectors is less than a preset threshold, the directions and angles of the four groups of control point change vectors are averaged to obtain a total control point change vector OVn. The trajectory checking unit obtains all total control point change vectors and connects the starting end of OVn+1 with the end of OVn to form a complete actual moving path.

5. A high-precision laser cutting machine control system according to claim 2, characterized in that: The method for the trajectory checking unit to calculate the vector difference of the change vector is: The trajectory checking unit calculates the direction deviation angle D and length difference L of the change vectors of the two groups of control points, and generates a vector difference C through formula analysis, C=(D+q)(L+j), where q and j are preset constant terms, and the value range of q and j is 3-7.

6. A high-precision laser cutting machine control system according to claim 2, characterized in that: The method for the trajectory checking unit to obtain vector superposition is: The trajectory verification unit draws a line segment with a length equal to the longitudinal axis difference in the longitudinal direction, draws a line segment with a length equal to the transverse axis difference in the transverse direction, and translates the line segment in the longitudinal direction, translates the starting point of the line segment in the longitudinal direction to the end point of the line segment in the transverse direction, and then connects the starting point of the line segment in the transverse direction with the end point of the line segment in the longitudinal direction to obtain a new line segment with a direction and length, which is recorded as a control point change vector.

7. A high-precision laser cutting machine control system according to claim 2, characterized in that: The path verification signal generated by the trajectory verification unit includes a path verification pass signal and a path verification fail signal; The trajectory checking unit assigns a preset path width to the actual moving path and the output trajectory, and overlaps the actual moving path with the starting point of the output trajectory, and divides the output trajectory and the actual moving path into i sections. If the actual moving path and the output trajectory always overlap in the i-th section, it is recorded as a normal section, otherwise, it is recorded as an abnormal section. The trajectory checking unit counts the number of occurrences of the abnormal section in the i sections and records it as a normal ratio; If the normal ratio is greater than or equal to the preset ratio threshold, a path check pass signal is generated; if the normal ratio is less than the preset ratio threshold, a path check fail signal is generated.

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